The present invention relates to a tracked load carrying vehicle comprising a chassis; an engine mounted on the chassis for propelling the vehicle; an output shaft driven by the engine; two parallel tracks provided on either side of the chassis, with each track running over a plurality of wheels, and with at least one wheel associated with each track being adapted to be driven by the output shaft of the engine for driving the track; and a control lever for steering the vehicle. The load carrying vehicle is primarily intended as an aid for transporting heavy objects in woods and fields, all the year round. For example, such vehicles may be used for pulling logs in the woods, for the transportation of plants in connection with new plantation in clearings, and for the transportation of carcases in connection with hunting.
Load carrying vehicles for the above mentioned purposes are previously known. These vehicles are either of the snow-scooter-type having tracks at the rear and turnable runners or wheels in front, or tracked special vehicles having particular equipment, for example a hoist. These prior art vehicles have the disadvantage in common that they are difficult to handle in wood-land where the free space available is limited, because of their limited steering capacity. Moreover, vehicles steered by means of runners or wheels have a large turning radius, and prior art vehicles of other types have had a low steering capacity or no steering capacity at all, so that a change of direction must be provided by turning the vehicle, for example, by forcefull pulling on an operating arm attached to the vehicle. This later type operation is tiresome and time-consuming.
It is known to steer tracked vehicles, particularly heavy tracked vehicles and armoured cars, by disengaging and/or braking one of the tracks while continuously driving the other track, thus providing a turning of the vehicle. This steering method requires complicated mechanical steering devices which normally are controlled by a person who rides in or on the vehicle. An example on this type of steering is diclosed in U.S. Pat. No. 2,614,642.
It is also known to steer small load carrying vehicles by means of a control lever adapted to actuate a braking device for braking one or the other of two tracks or driving wheels. Such a device is disclosed in the U.S. Pat. No. 3,444,945. The steering device disclosed in this patent, however, comprises a differential, so that braking of one track entails a faster driving of the other track. If one track skids, no driving force at all is obtained from the other track. Such a device is not suitable for load carrying vehicles which must be operable under hard conditions in woods and fields all the year round.